Big Sister Must Raise Her Little Sister Right

Title auto-translated

Also known as Sistervention · 언니는 여동생을 바르게 키워야 합니다 · Eonnineun Yeodongsaengeul Bareuge Kiwoya Hamnida · I Need to Raise My Sister Properly · I Need to Raise My Sister Right · A Sister Must Raise Her Younger Sister Properly · An Older Sister Should Raise Her Little Sister Properly · The Older Sister Should Raise Her Younger Sister

Story by Dongnyeon · Art by Danbam · Updates every Sunday

Synopsis

After a traffic accident, she wakes up inside a romance fantasy novel as the half-sister of the story's future villain. Determined to prevent that villain's dark turn, she pours everything she has into steering her sister toward happiness — only to find herself hopelessly entangled with the Grand Duke Rexvill, a man with a fearsome reputation as a bloodthirsty killer. He corners her whenever she's near another man, interrogating her like a jealous lover, yet when she dares to ask whether he might have feelings for her, he flatly tells her she's talking nonsense. So why, exactly, does he seem so obsessed with every detail of her personal life?